Grinder

ABSTRACT

A grinder includes a generally vertical, rotatable shaft having at least one set of cutter blades driven thereby and a fan assembly mounted on the shaft below the cutter blades in position to receive output therefrom. The fan assembly includes a fan disc secured to the shaft and rotatable therewith. Fan blades are secured to the fan disc in a generally radial orientation. Each fan blade includes a bottom flange secured to a top surface of the fan disc, a web extending upwardly from the bottom flange and a top flange extending outwardly from the web in a direction of rotation of the fan disc. The fan blades are preferably moveably mounted to the fan disc such that the angle of the fan blades relative to a true radial orientation can be adjusted.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. Nonprovisionalpatent application Ser. No. 13/111,353, filed May 19, 2011, which was acontinuation application of U.S. Nonprovisional patent application Ser.No. 12/493,470 filed Jun. 29, 2009 (now U.S. Pat. No. 7,950,601), bothof which are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to grinders, mills or shredders used toconvert a material from an unprocessed state to a processed state havinga reduced particle size.

BACKGROUND OF THE INVENTION

Grinders, shredders or mills are well known devices for reducing theparticle size of a material. For example, U.S. Pat. No. 5,192,029 toHarris and U.S. Pat. No. 5,680,994 to Eide et al. each disclose millsfor grinding garbage. Each of these mills includes a rotor rotatablymounted in a generally octagonal housing. The rotor includes a generallyvertical shaft and a plurality of blades or hammers mounted on theshaft. Garbage is admitted into the housing through an inlet near thetop of the housing and is impacted by the blades of the rotor. Materialof a reduced particle size is removed from the mill through an outletnear the bottom of the housing. The ground garbage can be sent to alandfill where it will take up less room than unprocessed garbage, or itcan be composted or recycled, depending on the included materials. Ifthe material is to be shipped, it can be shipped more efficiently due toits reduced size and greater density.

The mill of Eide et al. '994 further includes a fan or impeller which ismounted on the rotor shaft below the cutting blades. The fan is intendedto create airflow which acts to move material through the mill and toexpel it from the outlet. The fan generally comprises a fan disc mountedto the rotor shaft which has a plurality of radially extending lengthsof angle iron mounted thereon. One flange of each angle iron is boltedto the fan disc and the other extends upwardly from the disc to act as afan blade. The angle irons are fixedly mounted to the fan disc and nomeans are provided for adjusting the airflow for different materials orgrinding conditions.

It should be noted that, in addition to moving material through themill, the airflow from the fan also acts to remove moisture from thematerial as it is being ground. Since different materials and differentgrinding conditions produce different moisture levels in the material,it would be advantageous if the rate of airflow could be adjusted.

SUMMARY OF THE INVENTION

The present invention is a grinder of the general type disclosed aboveand including an improved fan assembly. The fan assembly includes fanblades having an additional top flange which extends generally in thedirection of rotation of the fan disc. The top flanges increaseefficiency by inhibiting air from flowing over the tops of the fanblades and thereby drawing more air through the system. The fan bladesare adjustably mounted to the fan disc so that they can be repositionedfor increasing or decreasing airflow through the grinder.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a grinder according to the presentinvention.

FIG. 2 is a cross sectional view of the grinder taken generally alongline 2-2 in FIG. 1.

FIG. 3 is a cross sectional view of the grinder taken generally alongline 3-3 in FIG. 2.

FIG. 4 is top plan view of the grinder.

FIG. 5 is a bottom plan view of the grinder.

FIG. 6 is a side elevational view of the grinder.

FIG. 7 is an enlarged fragmentary cross-sectional view similar to FIG. 2showing mounting detail for angle deflectors which form a portion of thegrinder.

FIG. 8 is an enlarged fragmentary cross-sectional view similar to FIG. 3showing a taper lock hub used for mounting cutter discs which form aportion of the grinder.

FIG. 9 is a cross-sectional view of the taper lock hub taken generallyalong line 9-9 in FIG. 8.

FIG. 10 is a cross-sectional perspective view taken generally along line10-10 in FIG. 1 and showing a fan assembly which forms a portion of thegrinder. One fan blade of the fan assembly has been removed to showdetail which would otherwise be obscured by the removed blade.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure. The drawings constitute a part of thisspecification and include exemplary embodiments of the present inventionand illustrate various objects and features thereof.

Certain terminology will be used in the following description forconvenience in reference only and will not be limiting. For example, thewords “upwardly,” “downwardly,” “rightwardly,” and “leftwardly” willrefer to directions in the drawings to which reference is made. Thewords “inwardly” and “outwardly” will refer to directions toward andaway from, respectively, the geometric center of the embodiment beingdescribed and designated parts thereof. Said terminology will includethe words specifically mentioned, derivatives thereof and words of asimilar import.

Referring to the drawings in more detail, the reference number 1generally designates a grinder according to the present invention. Thegrinder 1 includes a rotor 3 rotatably mounted in a housing 5. The rotor3 includes a generally vertical shaft 7 and a plurality of cutter discs9 longitudinally mounted on the shaft 7 and extending radially outwardtherefrom. A fan disc 10 is connected to the shaft 7 below the lowermostof the cutter discs 9 and spaced downwardly therefrom. For example, thedrawings show three cutter discs 9 denominated as discs 9 a, 9 b, and 9c from top to bottom, with the fan disc 10 spaced downwardly from cutterdisc 9 c.

Each cutter disc 9 has a plurality of cutter blades or hammers 11connected thereto which extend radially outward past the outer edge ofthe respective cutter disc 9. Four hammers 11 arranged at 90 degreeintervals are shown for each of the cutter discs 9. The hammers 11 areeach shown as being rigidly connected to the top surface of therespective cutter disc 9 by a pair of bolts 13. It is foreseen, however,that each hammer 11 could be fastened by only a single bolt 13 so as topivot or swing about the bolt 13 relative to the respective cutter disc9.

The housing 5 is generally octagonal in shape and includes a sidewall 14comprising eight sidewall sections 15, a top wall 17 and a bottom wall19. The housing 5 includes a door 21, comprising three of the sidewallsections 15, which is hingedly connected to a main housing 23 whichcomprises the remaining five sidewall sections 15. The top and bottomwalls 17 and 19 are each divided into respective first sections 17 a and19 a which form part of the main housing 23 and respective secondsections 17 b and 19 b which form part of the door 21. The line ofdivision between the first sections 17 a and 19 a and the secondsections 17 b and 19 b preferably extends through the axis of rotationof the shaft 7 such that the rotor 3 may be easily installed or removedthrough the opening provided by swinging open the door 21. An entrancechute 25 for admitting material into the grinder 1 is formed on the topwall 17 and communicates with the interior of the housing 5 through anopening in the top wall 17. A discharge chute 27 for dischargingmaterial from the grinder 1 is formed through the sidewall 14 andcommunicates with the interior of the housing 5 through an openingformed in the sidewall 14 just above the plane of rotation of the fandisc 10.

The shaft 7 of the rotor 3 is rotatably journaled to the main housingsection 23 by upper and lower bearings 29 and 31 respectively. The upperbearing 29 is mounted in a pillow block 32 located immediately above thetop wall 17 and connected to an upper framework 33 which is fixed to thetop wall 17. Similarly, the lower bearing 31 is mounted in a pillowblock 34 located immediately below the bottom wall 19 and connected to alower framework 35 which is fixed to the bottom wall 19.

Each sidewall section 15 includes a sidewall framework 37 comprising aplurality of horizontal ribs 39 extending between vertical ribs 41. Arespective replaceable wear plate 43 covers the interior of eachsidewall framework 37. Mounted to the interior surface of each wearplate 43 are a plurality of angle deflectors 45, the number of angledeflectors 45 on each sidewall section 15 being equal in number to thenumber of cutter discs 9. As best seen in FIG. 7, each angle deflector45 includes a vertical flange 47 positioned in abutment against theinterior surface of the respective wear plate 43 and a horizontal flange49 which extends inwardly from the respective sidewall section 15. Theangle deflectors 45 are positioned such that the horizontal flanges 49are each in general alignment with the outer edge of a respective one ofthe cutter discs 9 such that the respective hammers 11 move in closelyspaced relation to the upper surface of the horizontal flange 49. Asshown in FIG. 3, the ends of the angle deflectors 45 are cut at an angle(67.5 degrees) such the horizontal flanges 49 of angle deflectors 45 onadjacent sidewall sections 15 cooperate to form octagonal shelves whichextend continuously around the interior of the housing 5.

The angle deflectors 45 are mounted to the respective sidewall sections15 in such a manner that the position of each angle deflector 45 can befine tuned to insure proper alignment with the respective cutter disc 9.Referring again to FIG. 7, a plurality of bolts 51 (three shown in FIG.6) extend through holes in the vertical flange 47 of each of the angledeflectors 45, through oblong or oversize openings 53 in the respectivewear plate 43, and through horizontal holes in a respective adjustmentblock 55. The adjustment blocks 55 are each connected to the sidewallframework 37 by vertical bolts 57 which extend through aligned holes inthe adjustment block 55 and in a respective one of the horizontal ribs39 of the respective sidewall framework 37. Shims, washers or spacers 59can be placed around the vertical bolts 57 between the adjustment block55 and horizontal rib 39 to adjust the height of the adjustment block 55and connected angle deflector 45 within the range of the oblong openings53 in the respective wear plate 43.

A gap A is defined between the outer edge of each cutter disc 9 and theinner edge of the horizontal flanges 49 of the respective angledeflectors 45. The cutter discs 9 a, 9 b, and 9 c are of somewhatincreasing diameter from the top to the bottom of the grinder 1 suchthat the gap A decreases.

Referring to FIG. 2, the positions of the cutter discs 9 and fan disc 10along the shaft 7 are also adjustable due to the use of taper lock hubs61 to connect the discs 9 and 10 to the shaft 7. As best seen in FIGS. 8and 9, each hub 61 includes an inner hub member 63 and an outer hubmember 65. The respective cutter disc 9 or fan disc 10 is connected tothe outer hub member 65, such as by welding. The shaft 7 includes arespective keyway formed therein for each of the discs 9 and 10. Eachkeyway 67 receives a key 69. The inner hub member 63 includes a shaftreceiver 71 with a keyway 73 sized to receive the key 69. The inner hubmember 63 includes a split 74 which allows it to be compressed againstthe shaft 7 and a tapered outer surface 75. The outer hub member 65 hasa central bore 77 sized to receive the inner hub member 63 and an innersurface 78 tapered to match the outer surface 75 thereof. A plurality offastener receivers 79 are formed between the inner hub member 63 andouter hub member 65 and receive threaded fasteners 81 for drawing theinner hub member 63 into the central bore 77 of the outer hub member 65.

With the fasteners 81 loose and the inner hub member 63 uncompressed,the hub 61 (and attached cutter disc 9 or fan disc 10) can be movedalong the shaft 7 and repositioned anywhere within the limits of thelength of the respective key 69. Once the cutter disc 9 is in thedesired position, the fasteners 79 are tightened, drawing the inner hubmember 63 into the tapered central bore 77 of the outer hub member 65and compressing the inner nub member 63 against the shaft 7 to retainthe hub 61 and disc 9 or 10 in position.

Referring to FIG. 10, the fan disc 10 forms part of a fan assembly 83which acts to provide airflow through the grinder 1 and to therebyimprove drying of the material, to help move material through thegrinder 1, and to expel the ground material through the discharge chute27. The fan assembly 83 includes a plurality of fan blades 85 which areaffixed to the upper surface of the fan disc 10 in a generally radialorientation. Four fan blades 85 are provided in the embodiment depictedwith three of the fan blades 85 being shown in FIG. 10. The fourth fanblade 84 has been deleted to show detail which would otherwise beconcealed by the deleted fan blade 85. The fan blades 85 each include abottom flange 87 securable to the fan disc 10, an upwardly extending web89, and a top flange 91 which extends outwardly from the web 89 in thedirection of rotation of the fan disc 10 (designated by arrow B). Morespecifically, in a preferred embodiment of the fan blade 85, the web 89extends generally vertically upward from the leading edge of the bottomflange 87 (in the direction of rotation B of the fan disc 10). The topflange 91 then extends generally horizontally outward from the top edgeof the web 89, again in the direction of rotation of the fan disc 10. Itis foreseen, however, that the angles between the bottom flange 87, web89 and top flange 91 could be other than right angles.

The bottom flange 87 of each of the fan blade 85 has a plurality ofmounting holes formed therein for receiving fasteners 95 (three shown)used to connect the fan blades 85 to the fan disc 10. The fan disc 10has mounting holes 97 formed therein for receiving the fasteners 95. Itis preferred, however, that there be extra mounting holes 97 in the disc10 to allow the blades 85 to be selectively repositioned to adjust theairflow through the grinder 1. For example, the disc 10 is shown in thedrawings as having a single mounting hole 97 a proximate the outer edgeof the disc 10 for the outermost of the fasteners 95. The remainingfasteners 95 are provided with multiple mounting holes 97, arranged inarcuate rows. Five mounting holes 97 b are shown for the middle fastener95, and five mounting holes 97 c are shown for the innermost fastener95. By selectively pivoting the fan blades 85 about the fastener 95 inthe outermost hole 97 a and selecting different pairs of the mountingholes 97 b and 97 c, an operator of the grinder 1 can adjust the angularorientation of the fan blades 85 relative to a true radial orientationand thereby increase or decrease the airflow through the grinder 1 tobest suit specific materials to be ground and operating conditions.

The rotor 3 of the grinder 1 is driven by a motor 99 which may be, forexample, an electric or hydraulic motor. The motor 99 is mounted to oneof the sidewall sections 15 and includes a shaft 101 which is operablyconnected to a lower portion of the shaft 7 below the bottom wall 19 ofthe housing 5, such as by a chain and sprocket or belt and sheave system103.

The grinder 1 may be mounted on any suitable supporting structure,including a trailer (not shown) if it is desired to make the grinder 1portable. Suitable conveyors may be provided for moving material intothe inlet 25 and away from the outlet 27.

It is to be understood that while certain forms of the present inventionhave been illustrated and described herein, it is not to be limited tothe specific forms or arrangement of parts described and shown. As usedin the claims, identification of an element with an indefinite article“a” or “an” or the phrase “at least one” is intended to cover any deviceassembly including one or more of the elements at issue. Similarly,references to first and second elements, or to a pair of elements, isnot intended to limit the claims to such assemblies including only twoof the elements, but rather is intended to cover two or more of theelements at issue. Only where limiting language such as “a single” or“only one” with reference to an element, is the language intended to belimited to one of the elements specified, or any other similarly limitednumber of elements.

What is claimed is:
 1. A grinder comprising: a housing having a topwall, a bottom wall, and a plurality of sidewall sections; a shaftrotatably mounted in the housing between the sidewall sections; a firstcutter disc mounted on the shaft and rotatable therewith; a plurality ofhammers mounted on the first cutter disc and extending outwardly past anouter edge of the first cutter disc; a fan assembly mounted inside thehousing below the first cutter disc, the fan assembly comprising: a fandisc secured to the shaft and rotatable therewith, the fan disc having adirection of rotation; a plurality of fan blades connected to a topsurface of the fan disc; each said fan blade having a web extendingupwardly from said fan disc and a top flange extending outwardly fromsaid web in said direction of rotation of said fan disc and, the top andbottom walls of the housing are each divided into first sections andsecond sections, wherein the second sections form part of a door to thehousing, and a line of division between the first sections and thesecond sections extends through an axis of rotation of the shaft.
 2. Thegrinder according to claim 1, wherein the rotor may be installed orremoved through an opening provided by an opening of the door.
 3. Thegrinder according to claim 1, wherein the housing is generally octagonalin shape and comprises eight sidewall sections.
 4. The grinder accordingto claim 3, wherein the door comprises three of the sidewall sectionswhich are hingedly connected to the housing, which comprises five of thesidewall sections.